Dendreon Announces Data on PROVENGE Potency and Long-Term Immune Responses in Androgen-Dependent Prost...( -- Data presented at 100th Annual Mee...)

-- Data presented at 100th Annual Meeting of the American Association for Cancer Research --

SEATTLE and DENVER, April 19 /PRNewswire-FirstCall/ -- Researchers from Dendreon Corporation (Nasdaq: DNDN) presented today data from its PROTECT (PROvenge Treatment and Early Cancer Treatment) or P-11 Phase 3 study suggesting that PROVENGE(R) (sipuleucel-T) induces long-term memory immune responses that are durable and can be maintained following boosting. The results of the study also indicate that CD54 upregulation on Antigen Presenting Cells (APCs), a measure of potency, is a correlate of immune activation.

P-11 is an ongoing Phase 3 clinical trial designed to evaluate the safety and biologic activity of PROVENGE in patients with non-metastatic androgen-dependent (hormone sensitive) prostate cancer who have had a prostate-specific antigen (PSA) recurrence following surgical removal of the prostate. Patients were randomized to PROVENGE or placebo following 3 months of hormone therapy. This study evaluated CD54 upregulation and peripheral immune responses in men enrolled in the trial.

PROVENGE or placebo was administered at weeks zero, two and four. A treatment booster infusion of PROVENGE or placebo was offered after confirmed PSA greater than or equal to 3.0ng/mL. Immune responses were measured pre-treatment, at weeks four and 13, and at four and 13 weeks following the booster infusion.

At the week zero dose of PROVENGE, the expression of CD54 on APCs was upregulated 5.8 fold. At the week two dose, it was 10.1 fold, significantly increased from week 0 (p < 0.001). The increase in CD54 upregulation persisted at week four (10.7 fold) and at the time of the booster infusion (12.0 fold). There was an increase in cellular immune response between pre-treatment and week four (p < 0.001), which persist
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